Abutment Macro Design and Peri-implant Tissues

The Influence of Abutment Macro-design on Peri-implant Tissue Dimensions for Guided Placed and Restored Implants

The aim of this study is to evaluate the effect of abutment macro-design on soft and hard tissue responses. This trial is designed as a randomized controlled clinical study in which two groups of fourteen partially edentulous patients will have as part of their treatment one implant placed in the maxillary premolar region.

Implant placement and abutment design will be planned with a computer software for guided implant treatment (SIMPLANT). The surgical implant placement will be performed under manufacturer's protocol by placing the implant platform 1mm below the buccal aspect of the osteotomy (Koutouzis et al 2013). Virtually designed, permanent CAD-CAM fabricated abutments (ATLANTIS, DENTSPLY) with different configuration of the subcritical contour (emergence shape) will be connected to the implants and temporary crowns will be delivered. Implants of the Group 1 will have permanent abutments with a concave configuration of the subcritical contour (emergence shape). Implants of the Group 2 will have permanent abutments with a convex configuration of the subcritical contour (emergence shape). The patients will be restored with single crowns 3 months following implant installation. A randomization protocol will be produced from a computer-generated list for the distribution of subjects in the two treatment groups.

General Inclusion criteria: - Age more than 21 years Absence of relevant medical conditions Availability for 12 month follow-up Specific Inclusion criteria: One missing tooth in the maxillary premolar region Presence of two adjacent teeth at the implant site Absence of periodontal disease Healed osseous architecture enough to receive an implant with a diameter of at least 3.5 mm and a sufficient amount of bone for placing implants with a length of at least 9 mm General Exclusion Criteria: - Pregnancy at the screening visit. Smoking more than 10 cig/day Specific Exclusion criteria: Adjacent implants Presence of periapical radiolucency at the adjacent teeth Missing adjacent teeth

Koutouzis T, Neiva R, Nair M, Nonhoff J, Lundgren T. Cone beam computed tomographic evaluation of implants with platform-switched Morse taper connection with the implant-abutment interface at different levels in relation to the alveolar crest. Int J Oral Maxillofac Implants. 2014 Sep-Oct;29(5):1157-63. doi: 10.11607/jomi.3411.

Koutouzis T, Koutouzis G, Tomasi C, Lundgren T. Immediate loading of implants placed with the osteotome technique: one-year prospective case series. J Periodontol. 2011 Nov;82(11):1556-62. doi: 10.1902/jop.2011.100751. Epub 2011 May 4.